A 79-year-old woman recently died in a fire at her Washington, DC, row house when "pack rat conditions" prevented firefighters from reaching her in time.1 A few days later, 47 firefighters from 4 cities spent 2 hours fighting a fire in a Southern California home before they were able to bring it under control. Floor-to-ceiling clutter had made it nearly impossible for them to enter the house.2

In its severe forms, compulsive hoarding can lead to fires, unsanitary conditions (eg, rat and roach infestations), broken bones from tripping on clutter, and other health and safety hazards, according to Sanjaya Saxena, MD, director of the Obsessive-Compulsive Disorders Program at the University of California, San Diego.

Much more needs to be known about this disorder, Saxena told Psychiatric Times. "We don't have great epidemiology," he said, "but our estimates are that from 1 to 2 million people in the United States have clinically significant compulsive hoarding symptoms that require treatment. . . . Unless clinicians know how to screen for [hoarding], they won't identify it."

Several recently published studies on the phenotype, genetics, and treatment of compulsive hoarding may assist clinicians in diagnosis and treatment. Michael Wheaton and colleagues3 studied 473 patients with obsessive-compulsive disorder (OCD), with the purpose of characterizing the hoarding phenotype. They used a strict definition of hoarding that combined hoarding items from the Yale-Brown Obsessive-Compulsive Scale-Symptom Checklist (Y-BOCS-SC) and a clinician-based rating of hoarding. The definition enabled them to distinguish individuals with serious hoarding problems from non-hoarders.

"In our phenotype study, about a quarter [24.3%] of individuals with OCD had hoarding symptomatology," said Wheaton, an intramural researcher in NIMH's Laboratory of Clinical Science. The research team found that persons with OCD and hoarding behaviors tended to be more impaired than their non-hoarding counterparts. Hoarders endorsed more total OCD symptoms, including ordering compulsions as well as contamination, sexual, religious, symmetry, and somatic obsessions. They suffered from a greater degree of global impairment than non-hoarders and had more comorbid psychiatric disorders, such as social phobia, substance abuse, and a trend toward bi-polar I disorder.

One intriguing finding Wheaton noted is that hoarders had significantly higher scores on the Beck Depression Inventory (BDI) without having higher rates of major depressive disorder or dysthymia. The lifetime prevalence rates of major depression and dysthymia were similar in hoarders and non-hoarders, he said. But it was the score on the BDI, a measure of current depressive symptomatology, that was elevated more in the hoarders.

"It's very speculative to think about, but . . . [this] may be more related to hoarding itself, in that the people who have hoarding are quite impaired by it and might, therefore, suffer from more depressive symptomatology," he said.